1. Field of the Invention
The invention is directed to an improved fuel injection device for an internal combustion engine.
2. Description of the Prior Art
A fuel injection device known from the literature, for example Dieselmotor-Management, Verlag Vieweg, 2nd ed. 1998, pp. 280 to 284, has a high-pressure pump, which supplies fuel to a reservoir connected to injectors disposed in the cylinders of the internal combustion engine. A fuel-supply pump is provided, which supplies fuel from a fuel tank to the suction side of the high-pressure pump. An electrically actuated control valve is also provided in order to adjust the fuel quantity that the high-pressure pump delivers to the reservoir. The control valve here is embodied in the form of a flow control valve, which adjusts a flow cross section in the connection of the fuel-supply pump to the suction side of the high-pressure pump. The control valve is disposed in the connection of the fuel-supply pump to the suction side of the high-pressure pump and adjusts the flow of fuel from the fuel-supply pump to the suction side of the high-pressure pump. In this instance, it is disadvantageous that the precision of the adjustment of the fuel quantity that the high-pressure pump supplies to the reservoir depends on the uniformity of the pressure generated by the fuel-supply pump and on the precise adjustment of the flow cross section by means of the control valve. Pressure pulsations generated by the fuel-supply pump and dispersions in the adjustment of the flow cross section result in fluctuations in the quantity of fuel delivered by the high-pressure pump. In addition, difficulties can arise if it is necessary for the high-pressure pump to deliver no fuel to the reservoir since this requires the control valve to completely close the flow cross section, which requires a complex design of the control valve. Alternatively, additional means must be provided in order, when the control valve has not completely closed the flow cross section, to divert fuel that is still flowing to the high-pressure pump away from it so that the high-pressure pump does not deliver this fuel.